Recoil-operated feeding apparatus for a combustion chamber used in aerial propulsion



R. H. GODDARD 2,536,597

RECOIL-OPERATED FEEDING APPARATUS FOR A COMBUSTION CHAMBER, USED INAERIAL PROPULSION Filed Sept. 5, 1946 2 Sheets-Sheet 1 Jan. 2, 1951 Jan.2, 1951 c R. H. GODDARD 2,536,597 RECOIL-OPERATED FEEDING APPARATUS FORA comsus'rzou CHAMBER USED IN AERIAL PROPULSION Filed Sept. 5, 194a 2Sheets-Sheet 2 0, Goddmd, away.

Petented Jan. 2, 1951 RECOIL-OPERATED FEEDING APPARATUS FOR A COMBUSTIONCHAMBER USED IN AERIAL PROPULSION Robert H. Goddard, deceased, late ofAnnapolis, Md., by Esther C. Goddard, executrix, Paxton, Mass., assignorof one-half to The Daniel and Florence Guggenheim Foundation, New York,N. Y., a corporation of New York Application September 5, 1946, SerialNo. 694,922

1 Claim.

This invention relates to combustion chambers of the type having opendischarge nozzles and adapted for use in rockets and rocket craft. Theinvention relates more specifically to the provision of improved feedingapparatus for such combustion chambers, which feeding apparatus isoperated by the recoil of the chamber as successive charges of thecombustion mixture are ignited therein. Improved automatic valves arealso provided, together with means for cooling the valves and thecombustion chamber walls.

The invention further relates to arrangements and combinations of partswhich will be hereinafter described and more particularly pointed out inthe appended claim.

Preferred formsof the invention are shown in the drawings, in which Fig.1 is a general plan view showing a combustion chamber associated with apreferred form of the invention, and with certain details omitted forclearness;

Fig. 2 is an enlarged plan view of the improved feeding apparatus,partly in section, and showing certain additional details omitted in thegeneral view of Fig. 1;

Fig. 3 is a further enlarged sectional plan view of one of the automaticvalves;

Fig. 4 is a sectional plan view of a modified valve construction;

Fig. 5 is an end view of certain parts, looking in the direction of thearrow 5 in Fig, 4; and

Fig. 6 is a side elevation of a liquid-cooled valve.

Referring ot Figs. 1 and 2, a combustion chamber C and discharge nozzleN are shown mounted to slide in a fixed supporting frame I0. Pumps I 2,l4 and I 6 are provided to deliver liquids to the combustion chamber C,the .pump I2 delivering liquid oxygen through a feed pipe (Fig. 2) to ajacket space 2| associated with the combustion chamber head 22.

The pump l4 delivers liquid fuel, as gasoline, through a feed pipe 24 toan annular jacket space 25 in the combustion chamber head 22. Theseliquids are sprayed from the jacket spaces 2| and 25 through sprayopenings 21 and 28, and the sprays of the two liquids intersect and areintermingled as indicated by the arrows in Fig, 2.

The pump I6 is connected by a feed pipe to an annular passage or volute3|, and is provided to supply water or an inert liquid which enters thecombustion chamber C tangentially through feed openings 32 and whichcools the thin wall of the combustion chamber. Additional annularpassages or volutes 34 and 35 may 40 mounted on a cross arm 4|, which inturn" is supported on the fixed frame '10 (Fig. 2). Liquid oxygen is fedto the cylinder 40 through a supply pipe 42.

A piston 45 is slidable in the cylinder 40, and leakage between theseparts is prevented by a bellows packin 45. The piston 45 is mounted on across brace 50 carried by a movable frame 5| (Fig. 2) which is mountedon and slidable with the combustion chamber C at each recoil of thechamber.

The longitudinal position of the chamber C and frame 5| is controlled bysprings 55 and 56 (Fig. 2) which yieldingly resist displacement of thechamber and frame in either direction from normal mid-position. Threadedstuds 59 and 58 may be used to increase or decrease the pressure ofeither spring.

Each pump is provided with a check valve V (Fig. 3) between the supplypipe, as 42, and the cylinder 40 and with a second check valve V betweenthe cylinder 40 and the feed pipe, as 20, which connects the pump to theassociated jacket space or volute.

Each check valve comprises a streamlined member 60 or 60a slidable in aperforated guide ring 54 and engaging a narrow seating surface 65. Aspring 66 normally seats the valve member .50, and a spring 61 seats thevalve 60a. The spring 66 is relatively light, and the spring'fil is juststrong enough to resist the tank or supply pressure, say thirty pounds,and to thus prevent flow from the cylinder 40 to the feed pipe, as 20,when no recoil is taking place.

With this construction. at each movement of the piston 45 to the rightor in the direction of the arrow a in Fig. 3, the check valve V willopen and the cylinder 40 will be filled with liquid. On return from therecoil. the piston 45 will be forced into the fixed cylinder 40. Thecheck valve V will immediately close, preventing return of the liquid tothe supply pipe 42, and the check valve V will open to deliver theliquid in the cylinder 40 to the feed pipe 20.

Consequently, a measured quantity of liquid will be deliveredto thecombustion chamber after each explosion therein, and the amountdelivered will naturally be proportionate to the cylinder capacity ofeach pump. By correctly proportioning the pum s, the fuel. oxidizingliquid and cooling liquid will be fed in the desired proportions to thechamber C.

Ignition in the chamber C may be under the control of a spark-plug 10(Fig. 2) wired to a source of current, as a battery B, and in ludingnormally spaced contact members H and 12, mounted on the fixed frame 10.The spark-plug l and the contact '12 are grounded and the contact H isinsulated. A screw 13 ad ustably mounted on the sliding frame closes thecircuit by engaging and moving the contact 1|. Ignition takes place asthe cylinder reaches for ward position after each recoil movement.

The bellows packing 46 substantially prevents leakage between thecylinder 40 and piston 45 during the recoil movements. Any slightleakage which may occur is returned to the supply pipe 42 through anexpansible drain connection 15.

If it is desired to increase the area of the check valve openings topermit more rapid fiow, the valve construction shown in Figs. 4 and 5may be utilized. In this case, the fixed cylinder 80 is provided with adisc 81 having a pluralit of port openings 82, and the movable valvemember comprises a movable spider 83 having port-covering portions 84. 4The spider 83 is mounted on a nonrotatable guide-rod 85 and is seated bya light spring 86. The piston 90 has a similar perforated end disc 9|and a spider 92 with port-closing portions 93 which are seated by alight spring The operation is the same as previously described but, ateach recoil movement, a plurality of port openings are uncovered,instead of the single opening found in the construction shown in Fig. 3.

For starting purposes, a hand lever I00 may be connected to the frame 5|b a link It". This lever may be moved in the direction of the arrow b tocharge the pump cylinders. Release of the handle allows the frame toreturn to normal position and with the usual pumping action.

Flow to the pump cylinders is preferably controlled by valves H0, Illand H2 (Fig. 2) which may be connected to a single operating rod I I4,by the use of which simultaneous suppl of all three liquids to the pumpsmay be effected.

Where one of the pumps, as the pump I (Fig. 6), is used to pump a verycold liquid, such as liquid oxygen, it may be desirable that this pumpshould be precooled. This may be accomplished by providing a coil I2!surrounding the pump cylinder and connected to the liquid oxy- 4 genstorage tank, one end of the coil being connected to the bottom of thetank and the other to the top. Circulation through the coil will thenprecool the pump cylinder.

The rate of feed may be controlled by varying the stroke of the slidingframe, as by an adjustable stop screw I30 (Fig. 1). The extent ofopening of the valves H0, Ill and H2 (Fig. 2) may also be adjusted by ascrew I3l.

Having thus described the invention and the advantages thereof, it isnot desired that the invention be limited to the details hereindisclosed, otherwise than as set forth in the claim, but what is claimedis:

In a rocket apparatus, a fixed frame, a combustion unit slidable byrecoil in said fixed frame on the firing of each successive charge of aliquid combustion mixture and said unit comprising a combustion chamberand a discharge nozzle permanently secured thereto, separate pumps forthe liquid fuel and for the liquid oxidizer in said combustion mixtureand each pump comprising a cylinder and piston, one part of each pumpbeing secured to said fixed frame and the other part of each pump beingconnected to and, movable with said combustion unit, the relativecylinder capacity of said pumps being selectively proportioned to thepredetermined desired relative proportions of fuel and oxidizing agentin the combustion mixture but all of said pumps having the same stroke,supply and delivery connections to said pumps, and .a. check valve ineachpump part opening toward said combustion chamber.

ESTHER C. GODDARD, Executria: 0/ the Last Will and Testament of RobertH. Goddard, Deceased.

REFERENCES CITED The following references are of record in the file ofthis patent:

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